A powerful car bomb killed a top police official in the southern Russian region of Ingushetia, in what authorities say could have been a suicide bombing (or by remote control). The attack, in the region located next to the breakaway region of Chechnya, also killed six other people.

Ingushetia's Deputy Interior Minister Dzhabrail Kostoyev was killed along with his two bodyguards when the car parked on a roadside exploded near Ingushetia's main city of Nazran.

Four civilians also died when their car hit Kostoyev's armored vehicle, which police say was thrown about 20 meters by the explosion.

Russian television showed pictures of the blackened, mangled wreckage of several cars surrounded by debris.

Several nearby buildings were also damaged by the force of the explosion, estimated to be about 50 kilograms of TNT.

Dmitry Kuralyov of the local prosecutor's office says personnel are conducting a thorough search of the wreckage from the incident that he called the work of terrorists.

Kostoyev was traveling in a convoy of three cars and had been under special guard after several previous attempts on his life.

Last August, he was injured when assailants detonated a remote-controlled land mine near his passing convoy.

Ingushetia has long been plagued by violence blamed on militants fighting the government of a region that borders war-torn Chechnya.

Law enforcement officials and buildings are often targeted; a major attack in Ingushetia two years ago killed 92 people.

Poverty, government corruption and instability blamed on the long-running war in Chechnya have fueled anger throughout the North Caucasus region, which is home to a patchwork of mostly Muslim peoples.

In another incident early Wednesday, police say unidentified gunmen killed a prison official in the republic of Karachayevo-Cherkessiya, which is located west of Ingushetia.

Shootings and bombings occur almost on a daily basis in Dagestan, located just to the east of Chechnya on the Caspian Sea.

Some analysts say the increasing instability threatens to spiral out of control, especially as various rebel groups increasingly adopt militant Islam as their ideology.

Russian troops have been battling separatist rebels in Chechnya since 1994 in a conflict the Kremlin claims is now over, although daily attacks occur regularly there as well.